Adjustable reamer.



G. B. CHADWICK.

ADJUSTABLE BEAMER.

ICATION l A 4, 1916.

APP 1,21 @,904. Patented Jan. 2, 1917n AAAAAAAAAAAAA WVE/VTDR:

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GEORGE B. CHADWICK, OIE' PORTSMOUTH, NEW HAMPSHIRE.

ADJUSTABLE BEAMER.

Specification of Letters Patent.

Patented Jan. 2, 1917.

Application filed March 14, 1916. Serial No. 84,060.

To all whom it may concern:

Be it known that 1, GEORGE B. CHADWICK, a citizen of the United States,residing at Portsmouth, in the county of Rockingham and State of NewHampshire, have invented certain new and useful Improvements inAdjustable Beamers, of which the following is a specilication.

This invention relates to reamers, taps and similar tools in which theblades are capable of radial adjustment, and is intended to provide asimple and ee'ctive arrangement for progressively adjusting the bladesin such a tool.

My invention is herein illustrated and described as embodied in acylindrical reamer in which the blades are driven at their front ends,as set forth in my co-pending application Serial No. 80,292, liledFebruary 24, 1916, and resides in certain features of construction andarrangement hereinafter explained in connection with the accompanyingdrawing, in which:

Figure l is a side elevation of the reamer, as preferably constructed;Fig. 2 is mainly a central longitudinal section through the same; Fig. 3is a transverse section on the line 3-3 in Fig. 2; Fig. 4 shows thefront end of the driving mandrel in rear elevation; and Fig. 5 is asectional view similar to Fig. 2, but showing the parts in a diEerentposition of adjustment.

The reamer illustrated in the drawing comprises a driving mandrel 2having at its front end a cylindrical enlargement 3 which constitutes aunitary part of the mandrel and is provided with a number of notches 4,each of which extends radially inward from the periphery of theenlargement and also longitudinally through the latter. These notches 4correspond in number with the detachable blades 5 employed in thereamer, eight of them being shown, although the precise number isimmaterial. The enlargement 3 is also provided on its rear face with alike number of rearwardly-extending projections 6, each of which islocated at the bottom of one of the notches 4 and has its rear face 7slanted inward and forward, its outer kface being preferably flush withthe bottom of the corresponding notch. On the mandrel 2 is mounted acylindrical shell 8 provided externally with longitudinally-extendinggrooves 9 which correspond in number, width and position with thenotches 4 but at their front end are enough deeper than said notches toreceive the projections 6, so that the front end of the shell is adaptedto abut against the rear face of the enlargement 3. A nut 10 mounted ona threaded portion 11 ofthe mandrel 2 behind the shell 8 serves to clampsaid shell in any given position of adjustment, as hereinafterdescribed.

In each of the grooves 9 and the corresponding notch 4 is located one ofthe blades 5the inner portion of which is cut away at its front end toprovide an angular recess 12 adapted to receive the corresponding projection 6, as shown in Figs. 2 and 5, the inner edge of the blade beingsupported by the shell 8. In the specic reamer illustrated each blade 5has a longitudinal cutting edge 13 extending parallel with the axis ofthe reamer and a transverse cutting edge 14 at the front end of theblade, sothat the tool is adapted to ream a cylindrical bore having aclosed bottom and to face the bottom of the bore at its periphery, butso far as my present invention is concerned it is immaterial whether theblades are shaped to provide a cylindrical tool or a tapering tool, orwhether they have cutting edges at their front ends or not. All of theblades employed, which are exactly alike, are simultaneously clamped inplace by means of a concave nut 15 mounted on an externallythreadedportion of the shell 8 and engaging the slanting rear ends of theseveral blades in the usual way, the clamping nut 15 being preferablybacked up by a lock nut 16.

As described thus far the construction is practically the same as thatshown and described in my (3o-pending application above referred to andhas the same advantage, namely, that when the reamer is in use thedriving power applied to the mandrel is carried forward and transmittedto the blades at their front ends where the heaviest duty is imposedupon them, so that the rear portions of the blades are practically freefrom twisting strains and hence are no-t liable to be broken ordistorted suihciently to prevent the reaming operation from forming atrue surface. 1n my prior construction, hov

ever, the blades are adjusted outward `by* placing shims 'beneath them,whereas in the present case l am enabled to dispense with the shims byforming the bottom of each groove 9 at an angle with respect to the axisof the reamer and causing the blades to rest directly on the shell 8 inall positions of ad- Y byvarying the longitudinal position of the shell8 on the mandrel 2. For example, Fig. 5 shows the parts in the positionwhich they occupy when the blades are expanded to the maximum extent,and when in this position the front end of the shell 8 is in contactwith the rear face of the enlargement 3., against which it is clamped bythe nut 10. i ln order to adjust theV blades inward from this positionthe nut 10 is first screwed backward, the shell 8 is then moved backwardon the mandrel to a suitable extent, and the blades are then slid inwardand forward on their slanting inner edges until the angular portion oneach blade which lies beneath the corresponding projection V6 is wedgedbetween said projection and the underlying portion of the shell 8, asshown in Fig. 2, whereupon the parts are clamped by setting up the nuts10 and 15 and the lock nut 16.

Fig. 2 shows the blades in an intermediate position of adjustment, theirinward movement being eventually limited by the engagement of theirfront portions with the bottoms of the notches 1l. To adjust the bladesoutward the nuts 15 and 16 are first screwed backward .on the shell 8 toa sufficient extent, the blades are then moved backward and outwarduntil they reach the nut 15, the shell 8 is then forced forward as faras possible and clamped by the nut 10, and finally the nuts 15 and 16are vagain set up tightly to clamp the blades in place. ln allVpositions of adjustment the front ends of the blades are held againstthe shell bythe projections 6, which enter the f angular recesses 12 toa greater-or less extent. Y

It willV be seen that the blade-adjusting arrangement above describednot only renders the use of adjusting shims unnecessary butl alsoenables the blades to be adjusted progressively, as distinguished from astepby-step adjustment. It is to be understood, however, that within thescope of the `appended claims the details of construction of theblade-holding means and of the other parts of the tool may be modifiedin various ways without departing from my invention, and that myimprovements are applicable to various types of reainers and similartools.

l claim:

1.` vifi-tool of the characterdescribed, comarising a. drivinO- mandrelrovided with an Y with respect to said enlargement, and means forsecuring'the blades in place. Y c -V 2. Atool of the characterdescribed-comprising a driving mandrel provided withjan enlargementhavingy blade-receiving-notches therein .and rearwardly-extendingprojections each located behind one ofthe notches, a shell mounted onthemandrelY behind said enlargement and provided with blade-receivinggrooves each located in alinement 'with one of the notches and havingits bottom slanted with respect to the axis of the mandrel, a set ofblades located in said-grooves and notches and having recesses Vtoreceive said projections, means for maintaining said shell in variouslongitudinal positionswith Y.

respect tosaid enlargement, and means for clamping the rear ends oftheblades in place. y Y

c 3. A tool of the character described, comprising a driving mandrelprovided with an enlargement having bladereceiving notches therein vandvrearwardly-extending projections each located behindone of the notchesa shell mounted on the mandrel behind sai enlargement and provided with'blade-receiving grooves each located in alinement with one ofthenotches and having its bot- Y tom slantedy with respect to the axisofthe mandrel, a nut mounted on a threaded portion of the mandrel behindsaid shell and adapted to engage the latter, a set of blades located insaid grooves and notches and having recesses to receive saidprojections, and a blade-clamping nut mounted Aonvthe shell and adaptedto engage the rear'ends of l.

the blades. Y,

e. A tool of the character described, comprising a driving mandrelprovided with an enlargement having blade-receiving notches therein andrearwardly-'extending .projections each located Vbehind one oftheAnotches and having an inwardly and forwardly slanting rear face, ashell mounted kon lthe mandrel behind said enlargement andprovided-withblade-receiving grooves each "lo-r Y cated in alinement with one ofthenotches and having its bottom slanted With respect a threaded portion ofthe shell behind said to the aXis of the mandrel, a set of blades bladesand adapted to engage the rear ends located in said grooves and notchesand havof the latter. 10 ing angular recesses adapted to receive theSigned at Boston, Mass., this eighth day respective projections, a nutmounted on a of March, 1916.

threaded portion of the mandrel behind said shell, and a blade-clampingnut mounted on A GEORGE B. CHADWICK.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

